purchaseDateMs property
For consumable, non-consumable, and non-renewing subscription products, the time the App Store charged the user's account for a purchased or restored product, in the UNIX epoch time format, in milliseconds. For auto-renewable subscriptions, the time the App Store charged the user’s account for a subscription purchase or renewal after a lapse, in the UNIX epoch time format, in milliseconds. Use this time format for processing dates.
Implementation
@JsonKey(name: 'purchase_date_ms')
final String? purchaseDateMs;